The present invention relates to a device on which a laser beam is reflected multiple times by a plurality of confronting concave mirrors, the reflected optical path is centralized to form an interactive region of high photon density, and an interaction target such as gas, liquid, a solid body, plasma, a particle beam or an electron beam is introduced into the interactive region to cause an optical interaction such as optical excitation, optical ionization, photolysis, optical dissociation, photosynthesis, optical generation and optical analysis.
Gas, liquid, solid bodies and particle beams perform strong optical interactions with laser beams of specified wavelengths corresponding to the atoms and molecules composing them. In order to cause such interactions in the conventional arts, a pair of confronting curvilinear mirrors are generally used for forming an optical resonator in which optical interactions are carried out.
In this case, a region of high photon density is centralized to the center of the resonator interior. Such a region is extremely too small and too short to reserve long interaction time of atoms and molecules passing through the region. In order to reserve sufficient possibility to store light, an aperture formed through each curvilinear mirror is designed as small as possible to reduce optical loss. As a result, introduction of beams, atoms and molecules into the interactive region is rendered to be highly difficult to practice sufficiently. It is additionally a recent trend to use laser beams of extremely short pulses. Use of such laser beams makes the interactive region extremely small in terms of time and space dimension and, consequently, it is almost infeasible to cause optical interactions effectively.
Use of gas flows and particle beams for optical interaction necessitates presence of large apertures for incidence and exit into and out of the interactive region. In addition, these interaction media are in most cases rather low in density and degree of interaction. In order to cause sufficient optical interactions of the gas flows and particle beams with the laser beam, it is necessary to reserve a large interaction region in terms of time and space dimension.
It is thus the primary object of the present invention to provide a novel optical interaction device which removes the above-described problems inherent to the conventional arts and assures high efficiency in use of laser beams.
It is another object of the present invention to provide an optical interaction device which is able to reserve large apertures for incidence and exit of interaction media and interaction targets, a large interactive region with high photon density and along interaction time.
According to the present invention, an optical interaction device includes a pair of confronting first and second mirror sets each of which is made up of a plurality concave mirrors disposed in a annular arrangement around a common axis of the interactive region.
A laser beam generated by laser beam generating means is led to one concave mirror selected from the first mirror set via a laser beam guide means. Each concave mirror in the first mirror set reflects an incident beam to pass it through a prescribed position on an axis of the interactive region to direct a reflected beam to a corresponding concave mirror in the second mirror set. As a result, an interactive region of high photon density is formed at a position where reflected beams are centralized.
Each concave mirror in the second mirror set reflects incident beam from a corresponding concave mirror in the first mirror set to direct it to an adjacent concave mirror. As a consequence, each laser beam reciprocates between the first and second mirror sets whilst sequentially moving in the circumferential direction of the first and second mirror sets.
Interaction between the laser beams and the interaction target takes places in an interaction region where the laser beams pass collectively.
On the optical interaction device in accordance with the present invention, incident laser beams to the concave mirrors of the first, mirror set are reflected in a collected fashion and centralized at a focus on an axis of the interactive region. Then, each reflected beam can be directed to a corresponding concave mirror of the second mirror set. Thus, a interaction region of high photon density can be formed at a position where the reflected beams are centralized.